Lake Superior expected to rise slightly next month

NEWS RELEASE

INTERNATIONAL LAKE SUPERIOR BOARD OF CONTROL

***************************** Temporary closure of Gate 1 and update on Lake Superior outflow

The International Lake Superior Board of Control, under authority granted to it by the International Joint Commission, has set the Lake Superior outflow to 1,560 cubic meters per second (m3/s) (55.1 thousand cubic feet per second (tcfs)) for the month of September, effective September 3.

This is the outflow recommended by the regulation plan for the month of September and is the same as the August outflow.

The September outflow will be released by discharging about 1,440 m3/s (50.9 tcfs) through the three hydropower plants and passing most of the remaining flow through the control structure at the head of the St. Marys rapids.

The gate setting of the control structure will be maintained at the existing setting equivalent to one-half gate open (four gates open 20 cm, or about eight inches each).

The International Joint Commission has granted authority to Brookfield Renewable Power to make temporary closures of Gate 1 that supplies the Fishery Remedial Works.

Gate closures are required to facilitate the completion of refurbishment of the Canadian portion of the Compensating Works.

Gate 1 may be closed for periods of less than a day at any time until September 15.

An approved gate opening/closing protocol will be followed to minimize any adverse impacts on the fishery.

This past month the water supplies to the Lake Superior and Lake Michigan-Huron basins were below normal.

Lake Superior is currently 1 cm below its chart datum level.

The level of Lake Superior is expected to remain stable or rise slightly in September.

Currently, the Lake Superior level is about 33 cm (13 inches) below its long-term average beginning-of-September level, and is 23 cm (9 inches) lower than the level recorded a year ago.

This past month the level of Lake Superior rose 3 cm (1 inch), while on average it rises 1 cm (0 inches) in August.

The level of Lake Michigan-Huron fell 6 cm (2 inches) during August, while on average it falls 5 cm (2 inches) during August.

The level of Lakes Michigan-Huron is now about 33 cm (13 inches) below its long-term average beginning-of-September level, and is 22 cm (9 inches) lower than it was a year ago.

Currently Lakes Michigan-Huron is 20 cm (8 inches) above its chart datum level.

The level of Lakes Michigan-Huron is expected to fall in September.

The board continues to monitor conditions both on Lake Superior and downstream and will advise the International Joint Commission accordingly on those conditions.

Major General John W. Peabody, commander, Great Lakes and Ohio River Division, U.S. Army Corps of Engineers, is the United States board member.

Mr. David Fay is the board member for Canada.

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